Answer:

1. A substance that has a fixed chemical composition throughout is called a pure substance such as water, air, and nitrogen. A pure substance does not have to be of a single element or compound

2. Characteristics and Properties Of Pure Substances

•Pure substances are mostly homogeneous in nature containing only one type of atoms or molecules.

•These substances mainly have a constant or uniform composition throughout.

•The substances have fixed boiling and melting points.

•A pure substance usually participates in a chemical reaction to form predictable products.

3. A pure substance is a form of matter that has a constant composition and properties that are constant throughout the sample. Mixtures are physical combinations of two or more elements and/or compounds. Mixtures can be classified as homogeneous or heterogeneous.

Explanation:

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Answer:

1.Pure substances are substances that are made up of only one kind of particles and has a fixed or constant structure.

Pure substances are further classified as elements and compounds.

2.Pure substances are mostly homogeneous in nature containing only one type of atoms or molecules.

These substances mainly have a constant or uniform composition throughout.

The substances have fixed boiling and melting points.

3.pure substances are the substance that consist only one type of material such as elements compound and elements.

Explanation:

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